Abstract

Background

The epidermal growth factor inhibitors cetuximab and panitumumab are associated with hypomagnesaemia. Proton pump inhibitors (PPIs) also have a similar association. The aim of our study was to determine whether patients on both classes of agents develop more significant levels of hypomagnesaemia; which might have potential therapeutic implications.

Methods

This study was performed as a retrospective cohort analysis. Fifty consecutive patients treated with cetuximab or panitumumab were selected from our oncology database. Their medical records were reviewed to determine: if they were receiving PPI therapy or other agents contributing to hypomagnesaemia, if they received magnesium supplementation, and the presence of depressive illness. Magnesium levels before, during and after treatment were recorded. Linear mixed-effects models and logistic generalised estimating equation (GEE) models were used for statistical analysis. Unstructured covariance structure was used within the linear mixed-effects model as it resulted in the model of best-fit.

Results

Cetuximab and panitumumab were associated with significant reductions in serum magnesium levels (p

Conclusions

EGFR inhibitor therapy is associated with hypomagnesaemia. There was a correlation between depression and low magnesium levels. Further investigation is warranted to evaluate the links between these medical conditions, and the role of PPI therapy and magnesium supplementation.